In semiconductor components, in particular, e.g., in corresponding integrated (analog or digital) computing circuits and/or semiconductor memory devices, as well as in other electric circuits or—more generally—signal-processing systems, filter circuit arrays are frequently employed, e.g., high- and/or low-pass filter circuit arrays.
A high-pass is a filter circuit array that transmits the signals including high frequencies substantially unchanged, and causes an attenuation, and as a general rule a phase advance, in signals including low frequencies.
In contrast, a low-pass is a filter circuit array wherein signals including low frequencies are substantially transmitted unchanged; in the case of signals including high frequencies, an attenuation, and as a general rule a phase lag, is caused.
Passive high- and/or low-pass filter circuit arrays include one or several resistors, and—as an energy storage—one or several capacitive components (in particular, e.g., capacitors) (and/or one or several inductive components (in particular, e.g., coils)).
In comparison, so-called active filter circuit arrays include as a general rule—besides passive components such as resistors and capacitors—one or several active components, in particular operational amplifiers.
This results in a relatively high complexity in terms of circuitry.
If several conventional filter circuit arrays are arranged in series (so-called cascading), current or voltage outputs must frequently be converted into voltage or current outputs, or current or voltage inputs into voltage or current inputs.
Here the occurrence of undesirable, parasitic filters is frequently a drawback.
Conventional filter circuit arrays in which the transfer function has a positive or negative zero frequently comprise a differentiating circuit, which may be of disadvantage in terms of stability.
For these and other reasons, there is a need for the present invention.